<template>
  <view class="uni-numbox">
    <view
      @click="_calcValue('minus')"
      class="uni-numbox__minus uni-cursor-point"
    >
      <text
        class="uni-numbox--text"
        :class="{ 'uni-numbox--disabled': inputValue <= min || disabled }"
        >-</text
      >
    </view>
    <input
      :disabled="disabled"
      @focus="_onFocus"
      @blur="_onBlur"
      class="uni-numbox__value"
      type="number"
      v-model="inputValue"
    />
    <view @click="_calcValue('plus')" class="uni-numbox__plus uni-cursor-point">
      <text
        class="uni-numbox--text"
        :class="{ 'uni-numbox--disabled': inputValue >= max || disabled }"
        >+</text
      >
    </view>
  </view>
</template>
<script>
/**
 * NumberBox 数字输入框
 * @description 带加减按钮的数字输入框
 * @tutorial https://ext.dcloud.net.cn/plugin?id=31
 * @property {Number} value 输入框当前值
 * @property {Number} min 最小值
 * @property {Number} max 最大值
 * @property {Number} step 每次点击改变的间隔大小
 * @property {Boolean} disabled = [true|false] 是否为禁用状态
 * @event {Function} change 输入框值改变时触发的事件，参数为输入框当前的 value
 */

export default {
  name: 'UniNumberBox',
  props: {
    value: {
      type: [Number, String],
      default: 1
    },
    min: {
      type: Number,
      default: 0
    },
    max: {
      type: Number,
      default: 100
    },
    step: {
      type: Number,
      default: 1
    },
    disabled: {
      type: Boolean,
      default: false
    }
  },
  data () {
    return {
      inputValue: 0
    }
  },
  watch: {
    value (val) {
      this.inputValue = +val
    }
  },
  created () {
    this.inputValue = +this.value
  },
  methods: {
    _calcValue (type) {
      if (this.disabled) {
        return
      }
      const scale = this._getDecimalScale()
      let value = this.inputValue * scale
      let step = this.step * scale
      if (type === 'minus') {
        value -= step
        if (value < this.min * scale) {
          return
        }
        if (value > this.max * scale) {
          value = this.max * scale
        }
      }

      if (type === 'plus') {
        value += step
        if (value > this.max * scale) {
          return
        }
        if (value < this.min * scale) {
          value = this.min * scale
        }
      }

      this.inputValue = (value / scale).toFixed(String(scale).length - 1)
      this.$emit('change', +this.inputValue)
      this.$emit('input', +this.inputValue)
    },
    _getDecimalScale () {
      let scale = 1
      // 浮点型
      if (~~this.step !== this.step) {
        scale = Math.pow(10, String(this.step).split('.')[1].length)
      }
      return scale
    },
    _onBlur (event) {
      this.$emit('blur', event)
      let value = event.detail.value
      if (!value) {
        // this.inputValue = 0;
        return
      }
      value = +value
      if (value > this.max) {
        value = this.max
      } else if (value < this.min) {
        value = this.min
      }
      const scale = this._getDecimalScale()
      this.inputValue = value.toFixed(String(scale).length - 1)
      this.$emit('change', +this.inputValue)
      this.$emit('input', +this.inputValue)
    },
    _onFocus (event) {
      this.$emit('focus', event)
    }
  }
}
</script>
<style lang="scss" scoped>
$box-height: 35px;
/* #ifdef APP-NVUE */
$box-line-height: 35px;
/* #endif */
$box-line-height: 26px;
$box-width: 35px;

.uni-numbox {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex-direction: row;
  height: $box-height;
  line-height: $box-height;
  width: 100px;
}

.uni-cursor-point {
  /* #ifdef H5 */
  cursor: pointer;
  /* #endif */
}

.uni-numbox__value {
  background-color: $uni-bg-color;
  width: 50px;
  height: $box-height;
  text-align: center;
  font-size: $uni-font-size-lg;
  border-width: 1rpx;
  border-style: solid;
  border-color: $uni-border-color;
  border-left-width: 0;
  border-right-width: 0;
}

.uni-numbox__minus {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex-direction: row;
  align-items: center;
  justify-content: center;
  width: $box-width;
  height: $box-height;
  // line-height: $box-line-height;
  // text-align: center;
  font-size: 20px;
  color: $uni-text-color;
  background-color: $uni-bg-color-grey;
  border-width: 1rpx;
  border-style: solid;
  border-color: $uni-border-color;
  border-top-left-radius: $uni-border-radius-base;
  border-bottom-left-radius: $uni-border-radius-base;
  border-right-width: 0;
}

.uni-numbox__plus {
  /* #ifndef APP-NVUE */
  display: flex;
  /* #endif */
  flex-direction: row;
  align-items: center;
  justify-content: center;
  width: $box-width;
  height: $box-height;
  border-width: 1rpx;
  border-style: solid;
  border-color: $uni-border-color;
  border-top-right-radius: $uni-border-radius-base;
  border-bottom-right-radius: $uni-border-radius-base;
  background-color: $uni-bg-color-grey;
  border-left-width: 0;
}

.uni-numbox--text {
  font-size: 20px;
  color: $uni-text-color;
}

.uni-numbox--disabled {
  color: $uni-text-color-disable;
  /* #ifdef H5 */
  cursor: not-allowed;
  /* #endif */
}
</style>
